Black Sand is one of my favorite…

…exhibits. Blows my mind! So simple, but there’s something so satisfying to run your hands through the sand and play with the patterns you get. I’ve messed around with other magnetic-field visualizers, but this one feels like a step above…

Here is a new clip uploaded to ExploTV from Ken Finn about where we get our black sand ~ I remember my first time dragging for it in Ocean Beach, and it felt magical to be able to connect it directly to the exhibit when I got back to the Exploratorium.

(if you like a little California geography & Geology, the first two minutes.  Black Sand = 2 minutes onward)


Plastic Car


I talked to Sherry Marshall from the Oklahoma Museum Network today and she shared a little magnet experiment with me. She said she had been carrying around some neodymium magnets in her pocket that one day she was sitting in her car and got to wondering if she could use the magnets to search for metal components. She started running the magnets over everything in the car looking for metal and couldn’t find anything but a couple mounting screws in the stereo. Surprisingly, the interior of her car was almost entirely made up of other materials.

Homopolar Motors

Homopolar motors are very simple motors that consist of a battery, a magnet, and a bit of wire connecting the two. I made one with a coat hanger serving as part of the circuit, and the battery freely hanging off of it. Here are some pictures, and a very short video:

Floating Magnets

To brainstorm ideas for a magnet exploration I turned to one of the Exploratorium’s secret little archives of activity ideas, Paul Doherty’s personal website. He has a whole giant section on magnets with tons of interesting demos and experiments. Click Here to take a look at it.

I have been wanting to play around with one of these activities The Garden Of Magnets, for a long time now, because I love thinking about the way that simple systems can create complex patterns and interactions and this seemed like a perfect example. To make a floating magnet garden all you do is make a set of foam circles and attach a magnet to each one so that they all have the same orientation (I put staples in the foam and stuck each magnet to the staples so it would stay on the raft).

When I floated all my magnets in the water I was fascinated by the way they interacted with each other. Their behavior seemed to me to have a lot of personality, so at one point I added eyes to rafts and watched as they all moved over to give each other space, just like people do! Then I discovered that if I put one magnet in with the opposite orientation from all the others I got very different results. Eventually the rebel magnet would cause the entire system to collapse on itself, with all the magnets flipping over and grabbing onto each other until they were just one big pile and half the water had splashed onto the table!

Another interesting thing I noticed about this experiment is that the tone of this video became very important to me. I really wanted it to feel strange, and I wanted the little magnet rafts to come across as animate. I started this activity because I was interested in what it might show me about magnetic fields and how they interact, but in the end the narrative was what kept me playing with them for so long. A big part of taking time to try new experiences as a learner is to retain your ability to empathize with your visitors and students, and at the moment I’m finding it really easy to understand why narrative making opportunities get emphasized so much when we talk about exhibit and activity design.

Tin foil sculptures

I loved Cale’s tinfoil sculptures so much I decided to share the post on the Exploratorium blog. It inspired one of our staff to share a photo of one of her son’s tin foil sculptures back with me. I was both touched that she felt inspired to share this piece of art and impressed with the expressiveness this 8 year old breathed into his sculpture. The artist was once an Explainer and is now working on a masters in art in Yale. You can see he’s got the touch.


Magnets Have Nothing To Do With It

When I was an Explainer I always carried magnets around in my pocket, but oddly enough the main thing I did with them was demonstrate their ineffectiveness. When kids were asked “why do you think that’s happening,” one of the number one answers I heard was “magnets,” even at exhibits that had nothing what-so-ever to do with magnets. I would then pull out my magnets and let the kids test their idea.

it didn’t occur to me at the time, but looking back I realize that listening to common misconceptions like this one can reveal a lot about children’s deep understanding of phenomenon. As a thought experiment I decided to revisit the number one exhibit that attracted misplaced magnet theories and see if I could make some hypotheses about what those children were thinking. Here’s what I noticed:

1) This table is made of metal, a material that can be easily magnetized. Perhaps the children are aware of this phenomenon and associate metals with magnetism.

2) The rolling objects are round and black, just like some of the most common magnets found in science kits and on refrigerators. Perhaps the children associate round black objects, particularly ones with holes in them, with magnets.

3) The rolling objects tilt at an angle that appears to defy gravity. Perhaps the children suspect magnets when they encounter materials that seem to cause gravity defiance, because they know a magnet can be used to suspend objects that would otherwise fall.

I now plan on spending some time lurking near Turn table to see if I can find any magnet-confused subjects to test my theories on. This thought experiment has reminded me that underneath an incorrect answer there is often a correct idea worth digging for.

Foil as an insulator?

The announcement of foil as the material of choice came at the perfect time.  We were in the process of working ideas out for a week-long celebration called “Cool Science.”  Our marketing director passed along the great idea of a melting contest each afternoon of the celebration, which we coined “Afternoon Melt-down.”

So, I knew we could melt stuff outside, but what stuff? And how interesting would it be to literally watch ice cream melt on the sidewalk?  A whole flurry of ideas followed (melting candy, freezing marshmallow creme in nitrogen and watching it slowly melt; velveeta and butter soon followed-thanks to Terri Mouton and Sam Dean for the tasty and messy ideas).

I wanted to find a way that guests could participate in the experience and not stand outside of it.  Thanks to a flash of divine insight, the idea occurred to me to challenge guests to find ways to make popsicles melt more slowly.  This is where foil played an amazing role!  We gave guests choices of materials: bubble wrap, cotton balls,biodegradable packing peanuts, newsprint or foil.

They placed their “insulated” popsicles in the sun, next to my “naked” or uninsulated popsicle and we waited in the 110 degree heat until my popsicle melted-202 seconds!  Once my popsicle melted, then they would check their popsicle and were invited to eat their popsicle as a way to test the effectiveness of their insulating material.

Quite a few guests used foil to “protect” their popsicle, one stating that that foil could deflect the heat, another mentioning that light would bounce off the foil away from their popsicle.  Another guest did not use foil b/c he reasoned that it would make the popsicle melt faster, citing that foil is used to keep things hot in the oven.    While this activity has been very popular with guests who will brave the afternoon heat, the power I found in it was the ability to use the postings  here within our group to breathe life into my work and to find new ways to think about guest experiences with a simple material.

On a side note that has nothing to do with foil: another way we involved guests in Afternoon Melt-down was to create an online poll on, asking guests to text their prediction of the fastest melting objects to the site.  We project a graph of their answers in one of our studios, along with the directions on how to post. The graph changes each time a guest texts a response.